A wireless access point (AP) is a device that allows wireless communication devices to connect to a wireless network. The AP connects to a wired network, and can relay data between the wireless computing devices and wired computing devices on the network. The AP directly serves as the point of interconnection between the WLAN and the fixed wired network and allows wireless communication devices to be quickly and easily connected to a wired LAN. Each access point has full MAC functionality and sufficient program logic and processing power to allow it to enforce policies relating to access and usage. The wireless protocol terminates at the access point. A conventional wireless local area network (WLAN) can include a plurality of such access points.
With the proliferation of access point based wireless local area networks, to reduce the cost of implementing a WLAN, a wireless switch/access port architecture has been developed that employs simplified access ports in conjunction with a wireless switch device (or other centralized controller). These access ports, sometimes referred to as thin access points, have reduced MAC functionality in comparison to regular or “fat” access points, and many of the higher level MAC functions that would be implemented in an access point are implemented at the wireless switch device instead. The wireless switch device serves as a master controller that provides a single point of administration for all access ports it controls. Among other things, a wireless switch device configures controls, manages, and secures the environment for one or more access ports. In wireless switch/access port architecture, the wireless protocol terminates at the wireless switch.
As with many other types of networking devices, it is beneficial or sometimes necessary to deploy multiple wireless switch devices.
For instance, in some situations, a network architect will decide to deploy multiple wireless switch devices to divide a large WLAN with many access points into multiple IP (layer 3) subnets, where each wireless switch defines a subnet and controls one or more APs that belong to that subnet. Subdividing a WLAN into multiple subnets has several advantages (e.g., containment of broadcast traffic to a single subnet, limiting the effect of failure of network elements to a small network segment, etc.).
In other situations it is necessary to deploy multiple wireless switch devices. A wireless switch device has a fixed number of physical resources. When the number of access ports that need to be deployed in a WLAN exceeds the physical resources of the wireless switch, it becomes necessary to deploy another wireless switch device.
Alternatively, if a Wireless Internet Service Provider (WISP) provides wireless services to multiple independently operating customers, then the WISP needs to deploy one or more wireless switches per customer even though wireless switching resources of each wireless switch may not be fully utilized by a particular customer. When a new customer is added, a new wireless switch device needs to be added to the network, and when an existing customer leaves, the wireless switch for that customer needs to be removed and reconfigured for use by the next customer.
Wireless switches are highly specialized networking devices and can be relatively expensive. As such, one drawback of deploying multiple wireless switch devices is added cost. Moreover, when multiple wireless switch devices are deployed, each needs to be managed by the network administrator since they are physically separate devices.